Where can you find out TdF road closures?

A few of us off to the Pyrenees at the end of July and I've planned a few routes one taking in the Tourmalet. Now I know the roads are closed ahead of the caravan arriving but I remember a list of times being posted last time in went (2016). We are going from Lourdes to Tourmalet and then descending 1km to watch the pros climb.